HEIDENHAIN TNC 426, User Manual

Page: 255 / 502

HEIDENHAIN TNC 426, TNC 430 229
8.3 Cy
cles f
o
r Dr
illing, T
a
pping and Thr
ead Milling
RIGID TAPPING (Cycle 17)
The TNC cuts the thread without a floating tap holder in one or more
passes.
Rigid tapping offers the following advantages over tapping with a
floating tap holder
n
Higher machining speeds possible
n
Repeated tapping of the same thread is possible; repetitions are
enabled via spindle orientation to the 0° position during cycle call
(depending on machine parameter 7160).
n
Increased traverse range of the spindle axis due to absence of a
floating tap holder.
U Set-up clearance 1 (incremental value): Distance
between tool tip (at starting position) and workpiece
surface
U Total hole depth 2 (incremental value): Distance
between workpiece surface (beginning of thread) and
end of thread
U Pitch 3 :
Pitch of the thread. The algebraic sign differentiates
between right-hand and left-hand threads:
+ = right-hand thread
– = left-hand thread
Retracting after a program interruption
If you interrupt program run during tapping with the machine stop
button, the TNC will display the soft key MANUAL OPERATION. If you
press the MANUAL OPERATION key, you can retract the tool under
program control. Simply press the positive axis direction button of the
active tool axis.
Example: NC blocks
18 CYCL DEF 17.0 RIGID TAPPING GS
19 CYCL DEF 17.1 SET UP 2
20 CYCL DEF 17.2 DEPTH -20
21 CYCL DEF 17.3 PITCH +1
X
Z
1111
12
13
Machine and control must be specially prepared by the
machine tool builder for use of this cycle.
Before programming, note the following:
Program a positioning block for the starting point (hole
center) in the working plane with radius compensation R0.
Program a positioning block for the starting point in the
tool axis (set-up clearance above the workpiece surface).
The algebraic sign for the parameter total hole depth
determines the working direction.
The TNC calculates the feed rate from the spindle speed.
If the spindle speed override is used during tapping, the
feed rate is automatically adjusted.
The feed-rate override knob is disabled.
At the end of the cycle the spindle comes to a stop. Before
the next operation, restart the spindle with M3 (or M4).